A chopper-stabilized amplifier includes a first transconductance amplifier and a first chopper circuit coupled to an input of the first transconductance amplifier. A second chopper circuit is coupled to an output of the first transconductance amplifier. The chopper-stabilized amplifier also includes second and third transconductance amplifiers having inputs coupled to the output of the first transconductance amplifier. The second transconductance amplifier produces an output responsive to a first notch clock signal having a first phase relative to the chopping of the second chopper circuit. The third transconductance amplifier produces an output responsive to a second notch clock signal having a second phase relative to the first phase. The output signals produced by the second and third transconductance amplifiers are added to filter ripple noise at the outputs of the second and third transconductance amplifiers.

The present invention concerns a programmable power amplifier comprising:

an amplifier core transistor circuit connected to an amplifier output node; a switch connected to the amplifier core transistor circuit, the switch being configured to switch on and off the amplifier core transistor circuit; and a feedback circuit of the amplifier core transistor circuit. The feedback circuit comprises a digital-to-analog converter and an operational amplifier having a first input node configured to receive a first reference signal; a second input node connected to the digital-to-analog converter; and an output node for outputting an operational amplifier output signal and connected to the amplifier core transistor circuit for controlling the amount of current flowing in the amplifier core transistor circuit. The digital-to-analog converter has a programmable resistance value for controlling the resistance of the digital-to-analog converter to thereby adjust a digital-to-analog converter output signal fed to the second input node of the operational amplifier for controlling an amplifier output signal at the amplifier output node.

A linear amplifier is provided to have higher efficiency for an envelope tracking modulator. In one embodiment, a first stage amplifier circuit can be simply operated in a high gain mode or a high bandwidth mode for different applications, without using large chip area. In another embodiment, an output stage has a cascode structure whose dynamic range is controlled according to a voltage level of a supply voltage, to make a core device within the output stage have better protection and suitable dynamic range.

The disclosed technology relates to a method for improving performance of a feedback circuit comprising an amplifier and a feedback network, wherein the feedback circuit has at least one tunable component. In one aspect, the method comprises measuring first amplitude values at an input of the amplifier and second amplitude values at an output of the amplifier, estimating a linear open-loop gain of the amplifier based on both the amplitude values, estimating a linear finite gain error based on the estimated gain and the second amplitude values, subtracting the linear finite gain error from the first amplitude values to derive a set of samples containing second error information, deriving an signal-to-noise-plus-distortion ratio estimate based on the variance of the set of samples and a variance of the second amplitude values, and adjusting the feedback circuit in accordance with the signal-to-noise-plus-distortion ratio estimate.

A read-out circuit includes an operational amplifier configured to receive an input voltage through a positive input terminal; a feedback capacitor connected between an output terminal of the operational amplifier and a negative input terminal of the operational amplifier; a sensor charging and discharging circuit configured to charge or discharge a sensor during a first time; a switching circuit connecting the sensor and the operational amplifier during a second time after the sensor is charged or discharged; and a duty control circuit configured to determine a duty ratio of the first time and the second time according to a capacitance of the sensor.

In an embodiment an integration circuit has a first input terminal configured to receive a first input signal, a second input terminal configured to receive a second input signal, an output terminal to provide an output signal as a function of the first and the second input signal, a first and a second amplifier, each being switchably connected between the first or the second input terminal and the output terminal, and a capacitor which is switchably coupled in a feedback loop either of the first or of the second amplifier such that the capacitor and one of the first and the second amplifier form an inverting integrator providing the output signal. Therein the integration circuit is prepared to be operated in a first and a second subphase, wherein in each of first and second subphases one of the first and the second input signals is supplied to the inverting integrator and the respective other one of first and the second input signals is supplied to the respective other one of the first and the second amplifier.

A receiver front end capable of receiving and processing intraband non-contiguous carrier aggregate (CA) signals using multiple low noise amplifiers (LNAs) is disclosed herein. A cascode having a common source configured input FET and a common gate configured output FET can be turned on or off using the gate of the output FET. A first switch is provided that allows a connection to be either established or broken between the source terminal of the input FET of each LNA. Further switches used for switching degeneration inductors, gate capacitors and gate to ground caps for each legs can be used to further improve the matching performance of the invention.

Disclosed is a reconfigurable amplifier and an amplification method thereof, the amplifier includes an input selector, a first amplifying circuit, and a second amplifying circuit. The input selector is configured to select one of a voltage input and a current input based on a voltage measurement mode and a current measurement mode. The first amplifying circuit includes a first load element, and is configured to apply a voltage corresponding to the voltage input to the first load element in the voltage measurement mode and receive the current input in the current measurement mode and block a current flowing through the first load element. The second amplifying circuit is configured to mirror a current flowing through the first amplifying circuit in response to one of the voltage input and the current input and generate an output voltage based on the mirrored current.

A gain amplifier of a sensing circuit for sensing degradation of an OLED display panel, the gain amplifier comprising: an operation amplifier; and a plurality of gain amplifier cells sequentially coupled to the operation amplifier. Each of the gain amplifier cells comprises a plurality of capacitors each placed between two internal nodes of the gain amplifier cell, excluding a ground node, such that a voltage gain of the gain amplifier and a DC offset of the gain amplifier are determined according to capacitances of the capacitors without considering parasitic capacitance.

A signal coupling apparatus for transmitting transmission signals between a terminal and an antenna includes a terminal-side interface, at least one attenuation device and at least one connection signal arm for connecting the terminal-side interface with the attenuation device. At least a first transmission activity detection device is coupled with the connection signal arm for signaling purposes. The first transmission activity detection device is capable of generating a protection signal for controlling the attenuation device if a transmission power of a transmission signal is greater than a predetermined power. There is also described a method for operating such a signal coupling apparatus.